relations and habits of heteroptera. 21 



The Relation of Heteroptera to Other Insects 



All true insects can be separated into one or the other of 

 two great groups, based upon the kind of changes or trans- 

 formations which they undergo before reaching the adult or 

 winged stage. To one group, the Metabola, belong those in- 

 sects which undergo what is called a complete metamorphosis. In 

 this group there are four distinct stages, the egg, larval, pupal 

 and imago, in the order named. 



The second group, the Heterometabola, comprises those in- 

 sects in which the metamorphosis is incomplete; the young, when 

 hatched from the egg being wholly wingless and of the same 

 general form as the parent. As the insect grows it moults its 

 skin a number of times and wings develop gradually, there be- 

 ing no sharp line defining the larval and pupal stages. The 

 young of all stages are called nymphs and continue active and 

 feed from the time of hatching until they reach the final moult 

 and emerge therefrom mature or in the imago stage. 



It is to this second group, the Heterometabola, whose members 

 undergo an incomplete metamorphosis, that the Heteroptera, 

 the order of which this paper treats, belong. From other 

 orders of the group as the Orthoptera or locusts, Odonata or 

 dragonflies, etc., the Heteroptera may be known by having the 

 wings, when present, four in number, more or less net veined, the 

 outer or front pair more horny than the hind ones, folding flat on the 

 hack, their apical portion more membranous than the basal one ; front of 

 head not touching the coxae ; mouth parts sucking, consisting of a pro- 

 boscis or movable beak -which, when at rest, is concealed beneath the 

 body. The members of the order Homoptera possess a some- 

 what similar beak, and they and the Heteroptera are usually 

 considered as suborders of the order Hemiptera. However in 

 the Homoptera the outer wings cover the abdomen in a roof- 

 like manner and are usually of the same texture throughout ; 

 while the front of the head is much inflexed so that in repose 

 it is in contact with the front coxae. These and other differ- 

 ences lead me to treat the Heteroptera as a separate and dis- 

 tinct order. 



Habits of Heteroptera. 



Food and Mating Habits. — The food and mating habits of 

 the Heteroptera are almost as diversified as the species them- 

 selves. Uhler (1884, 205) has well said: "They are either 

 aerial, terrestrial, riparian, or aquatic. Some pass their lives 



